Quadratic counter

Counter target spell with three pips as the mana
cost and assign each anumber as follows, with the
first in the mana cost being a, the second one
being b, and the third being c.
{x} - 0, {0} and up - The number in the gray circle, {s} - 0, {w} - 1, {u} - 2, {b} - 3, {r} - 4, {g} - 5, {c} - 6,
Hybrid - 7, Phyrexian - 8
Put the numbers into the quadratic formula:
x= (-b +/- root(b2 - 4ac) )/2a You gain X life
and draw X cards (Round up). If X is a whole
number without rounding, you win the game.